Metallic packing.



W. J. WRIGHT.

METALLIC PACKING.

APPLICATION FILED MAY 25. 1911.

` Patented Feb. 20, 191.2.l

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WILLIAM JAMES WRIGHT, OE FRANKLIN, PENNSYLVANIA.

METALLIC PACKING.

Specification of Letters Patent.

Original application iiled October 17, 1910, Serial No. 587,599.

Patented Feb. 20, 1912. Divided and this application filed May 25,

Serial No. 629,417.

To all whom tt may concern:

Be it known that I, WILLIAM J. IVRIGHT, residing at Franklin, in the county of Venango and State of Pennsylvania, have invented certain new and useful Improvements in Metallic Packing, of which the following is a specification.

My invention has for its object to provide an improved metallic packing, particularly adapted for use on engine pistons, shafts and the like, and the invention has for its object to provide a packing ring that will expand evenly throughout and one of such construction that it can be cheaply manufactured and will eii'ectively serve its intended purposes.

Another object of my invention is to provide a packing ring in which the ends of the ring or band are overlapped lpreferably throughout a complete turn around the ring so they will not separate when the rim contracts to form an opening.

Invcarrying out my invention, I take a long strip or ribbon of a width slightly less than the width of the packing ring desired, and I wind it tightly in a spiral on a suitable mandrel. After which the strip is cut into rings of the required size, cut by a tool held at right angles to the axis of the mandrel, the pitch of the spiral being equal to the width of the packing so that the line of separation of the overlapping portions of the ring blank will extend in one complete turn and thereby avoid a direct cut or opening across the face of the ring and provide, as it were, a closedring when the saine is applied to the piston and in use.

In its more specific nature, the invention also includes those novel details of construction, combination and arrangement of parts, all of which will be first fully de.- soribed, then be specifically pointed out in the appended claims and illustrated in the accompanying drawings, in which Figure 1, is a view illustrating the inanner of winding the strip or band onto the mandrel to form the ring. Fig. 2, is an enlarged cross section on the liiie 2 2 of Fig. 1, the beveled edges of the strip being greatly exaggerated, for purposes of illustration. Fig. 3, is a view similar to Fig. 2, on the line 3 3 of Fig. 1, and hereinafter speciically referred to. Fig. 4, is a side elevation of a complete packing ring formed in accordance with my invention, the relative proportions of width to diameters and thickness of material being greatly distorted or exaggerated for purposes of illustration from what would usually be the practical proportions employed. Fig. 5, is a side elevation of the ring shown in Fig. 4. Fig. 6, is a developed view of the ring shown in Figs. 4 and 5. Fig. 7, is a section on the line 7-7 of Fig. 6.

Referring now to the accompanying drawings, in which like letters and numerals of reference indicate like parts in all of the figures, I take a suitable strip or band of steel, copper or'other suitable material of a uniform width throughout its length, the

band 1, however,

having its side edges 4 beveled to reduce the width of the lower face 8 to less than that of the upper face 2 ofthe strip 1, the amount of this beveling being dependent upon the thickness of the strip and the diameter of the mandrel on which the strip is to be wound. The strip 1 is next wound onto a mandrel M of any approved type in a manner such as indicated in Fig. 1, of the drawings. The mandrel M may be placed in a magnetic chuck or it may itself be magnetized to hold the strip 1 in place, if the strip 1 be of magnetic material, or a sleeve S may be slid over the wound strip to retain it in position on the man drel until the strip is cut into the form of rings. After the strip has been wound onto the mandrel -M a cutting tool is supplied to cut the strip along the lines L which are parallel planes normal to the axis of the mandrel M, thereby cutting rings of such width that the line of overlap 5 of the overlapping edges of the ring will commence at the point 6 (see Fig. 4) and make a complete turn around the ring terminating at a point 7 directly opposite to the point 6 in longitudinal alinement with the axis of the mandrel so that the line 5 extends throughout one ooinplete turn. In this way, by making the strip 1 of narrow width to form narrow width rings a fine feather edge of the material may be provided where it overlaps the mainbody portion of the ring section.

In Fig. 3, I have shown a section through the strip after it has been wound on the mandrel, the dotted lines indicating the original cross sectional outline of the strip (see Fig. 2) while the full lines indicate the final cross sectional outline of the strip packing after it has been tightly wound on the mandrel. In winding the strip on the mandrel the surface 3 being bent into a circle of a diameter less than that of the surface 2 will expand and were the strip originally of a rectangular cross section the lower surface 3 would expand laterally to a greater degree than the upper surface 2 and a tight contact. between the adjacent edges of the band l in its different folds could not be had. Therefore, the strip l is initially beveled on the sides as at 4L, to allow for its unequal expansion.

The preferred form of the packing ring after it has been cutfrom the spiral winding (see Fig. 4) is of a shape such as indicated in Fig. 6, when folded out into a lane. It will be observed by reference to Fig. 6 that the line f-a-b and the lines c-fZ-c are parallel to one another, and the lines a-c and b--fl are also parallel to each other, the lines y-c and b--e being also parallel to one another. The inner surface 3 of t-he ring when developed is bounded by the lines a-b, b-d, cl-0, c-ca and comprises a parallelogram. The outer surface 2 of the ring when developed is formed by the parallelogram f-ZJ-e-c-f. It will be noticed that by connecting the points b and @with a line 10, this line l() making an angle of 90 with the line @#6 and also with the line c-cl the line l() is equal to the width of the pack` ing ring desired. A line drawn from Z) to intersect the line af-c at right angles, being the line hwg, will give the widt-h of the strip which must be employed in order to provide a ring equal to the width of the line -c, the angles g/ and w respectively being right angles. It is then a comparatively easy matter to determine the width of strip necessary to be employed to produce a ring of a given width, knowing the width of the ring desired gives the value of the line 6 0, and knowing the circumference of the ring desired gives the value of the lines c-CZ and cz-b or @we and a-f, as the case may be, depending upon whether the circumference is the inner or outer circumference of the ring. Knowing these factors one can determine the value of the side b-rl or b-e, as the case may be, and knowing the value of this side, the value of the line b-g can be determined, thereby giving the width of strip necessary to use to make the ring of the width desired; the following formula may be used to determine its quantity, viz z-Let J-c equal the width of the packing ring desired, and let c-d equal the circumference of the ring, then b-rl is equal to Therefore b-g: :'--c: c-0Z: b-rL By constructing a packing ring in the manner described and disclosed a more effective packing of the part on which the ring is used can be had than is possible by the use of split packing rings in which the split or cut extends across the ring instead of extending around the ring through preferably a full turn, as before stated, by making a ring of this type and making the width of the ring small in proportion to the diameter of the same., the overlapping ends of the ring may be drawn out to a fine feather edge, as it were, so as to render such edge exceedingly fiexible, and cause it to hold up tightly against the main or body part of the ring as the packing is carried along by the piston, and should the packing ring be of slightly less width than the groove in which it is held, this condition would not result in leakage, but on the other hand, would be more or less beneficial when my packing is employed, for the reason that by using a packing in which the overlapping parts may be drawn out to a fine feather edge made very thin, a tighter contact at the .cut 5 can be had than is possible with packing rings split straight across or on a bevel as when such packing rings expand an opening is left between the ends through which leakage occurs which cannot be had with the use of my packing.

While I prefer to construct the ring as specifically herein described, in which the line of lap of the ring extends a complete turn around the ring, yet I do not wish to confine myself to this specific form, as the line of lap may make more than a complete turn or make less than a complete turn so long as the line of lap is of a sufficient length to prevent separation of the ring ends when they contract.

In this application I make no claim to the method of manufacturing the packing which method constitutes the subject matter of my original application filed October 1T, 1910, Serial #587,599, of which original application the present one is a divisional part.

From the foregoing description, taken in connection with the accompanying drawings, it is thought the complete construction, operation and advantages of my invention will be readily understood by those skilled in the art to which the invention appertains.

What I claim is 1. A packing ring which consists of a band or strip cut into a blank in the developed form of which is a parallelogram whose minor axis is equal to the width of the ring desired and a pair of diagonally opposite sides being each equal in length to the circumference of the ring desired.

2. A packing ring which consists of a band or strip cut into a blank in the developed form of which is a parallelogram whose minor axis is equal to the width of the ring desired and a pair of diagonally opposite sides being each equal in length to the circumference of the ring desired and lie at right angles to said minor axis.

3. A packing ring consisting of a band or strip bent into the form of a ring and having its ends extended to a feather edge whereby when said strip is folded into ring form the line of Contact between the cut edges of the strip will extend throughout a complete turn.

4. A packing ring consisting of a band or strip bent into the form of a ring and havsufficient to prevent separation of the ends of the ring when contracted.

WILLIAM JAMES WRIGHT.

Witnesses:

ROBERT L. ARMSTRONG, FRANK C. ERB.

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents, Washington, D. C. 

